Crushing mill



Feb. 21, 1939. A. w. FAHRENWALD CRUSHING MILL Filed May 7, 1954 4 Sheets-Sheet l gmc/rm D W @n M F W Q U w Q A Feb. 2l, 1939. A. w. FAHRENWALD CRUSHING MILL Filed May 7, .1934 4 Sheets-Sheet 2 e@ @s 59 /z AAW/m7 Feb. 21, 1939. A W. FAHRENWALD 2,147,833

,CRUSHING MILL Filed May 7, 1954 4 Sheets-Sheet 5 Feb. 2l, 1939. A. w. FAHRENWALD CRUSHING MILL 4 Sheets-Sheet 4 Filed May 7, 1934 [L 0552 n D05/ T/D/v UF du W Patented Feb. 21, 1939 UNITED STATESl PATENT oFFlcE CRUSHING MILL Arthur W. Fahrenwald, Moscow, Idaho Application May 7, 1934, Serial No. 724,336

5 Claims.

My present invention relates to improvements in crushing mills of the compound movement type, involving the utilization of a floating, gyratory, crushing head, and an inverted bowl-shaped concave or stationary crushing head, for use in crushing ores, rock, and othermaterials.

Due to the construction and arrangement of the operating parts of the mill, an unobstructed and free flow, or feed, of the material to the crushing elements is afforded, and a continuous supply of the material to be crushed is successively passed by gravity through an upper coarsecrushing zone and then through a lower flnecrushing zone, which crushing zones or spaces are formed between the two crushing elements or members.

An unobstructed feed hopper is located above the adit or coarse-crushing zone and the material is fed directly from the hopper to the zone, means being provided in the construction of the conical gyratory head and the `concave to throttle the crushing capacity of the mill at its mouth for the purpose of equalizing the crushing capacity of the adit and the exit zones in order that the former may not crush the material faster than the latter.

The concave is composed of two sections to provide the adit or coarse-crushing zone and the exit or fine-crushing zone, and means are provided for varying or adjusting the capacity of the adit zone to prevent overfeeding of material to the exit zone, thereby insuring a uniform passage of the material through the mill. This adjustment and regulation is accomplished by the use of a vertically adjustable crushing-jaw in the adit zone of the concave, which jaw may be independently adjusted with relation to the jaws of the gyratory head and with relation to the jaw of the exit zone.

Means are also provided for vertically adjusting the conical, gyratory crushing head and its spindle, from below, with relation to the concave for varying the capacity of the mill, and the bearings for the gyratory crusher head for both the lateral thrust and the vertical load of the eccentrically operated head are so arranged as to insure permanent and correct alinement and smooth operation of the spindle of the crushing head in its bearings.

The bowl and its sectional concave are held down upon the main frame of the mill by resilient means, in addition to gravity, in order that the jaws and other parts of the mill may be protected against breakage due to the entrance of an excessively large stone that is non-breakable,

(o1. sa-io) and a novel bearing is provided between the bowl and the main frame of the mill to insure a con-A tinuous surface contact and proper readjustment even though a portion of the bowl is lifted from the supporting frame.

Other novel features and combinations of parts are embodied in the crushing mill of my invention. all as will hereinafter be set forth and claimed. In the accompanying drawings I have illustrated one complete example of the physical embodiment` of my invention in which the parts are combined and arranged but it will be understood that various changes and alterations may be made in the exemplified structure within the scope of my claims, without departing from the principles of the invention.

Figure 1 is a vertical sectional view, partly in elevation, of the mill embodying my invention.

Figure 2 is a detail elevation of one of the resilient retaining devices for the bowl and its concave,

Figure 3 is an enlarged detail view of the gyratory crushing head and its spindle, also showing the bearings and other parts in section.

Figure 4 is an enlarged detail sectional view, with parts omitted, showing the relation of the jaws of the crushing head to those of the concave, and illustrating the adjustment of the adit jaws of the concave.

Figure 5 is an enlarged detail sectional view, as at line 5 5 of Figure 2.

Figure 6 is a fragmentary detail perspective view showing a pair of lugs, and Figure 'l is a View of one of the bolts for said-lugs, used in suspending the annular jaw of the exit section of the concave.

Figure 8 is a diagrammatic view showing the relation of the gyratory head to the concave, and indicating the choke crushing zone at the mouth of the mill, and the free-crushing zone extending from the first mentioned Zone to the discharge or bottom outlet of the mill. In the preferred form of the invention as shown in the drawings Iutilize a suitable foundation I, which forms a central discharge space for the crushed material, as it falls from the mill, and this space is indicated at 2. A flanged cylindrical frame, or machine base 3, is supported on the top of the foundation to form a housing that is open at top and bottom. At its top edge the housing is fashioned with an exterior, horizontal flange 4, and the exterior of thisj flange is fashioned as an annular groove 5 concave or curved in cross section for use as a bearing face for supporting the inverted bowl of the concave and its sectional jaws. At

suitable points about its periphery, the flange 4 is fashioned with a number of equidistant bolt holes 9 that extend vertically through the flange and outside of the periphery of the cylindrical housing or machine base.

The inverted bowl forming part of the concave and which is supported above the machine base or housing, is fashioned with a cylindrical portion 1 and an outwardly flaring, conical wall 9 that merges with a horizontally extending flange 9, and the horizontal flange 9 terminates in an overhanging annular flange I II having an innerconvex bearing face II that is seated in the complementary groove or bearing face of the top of the machine base or main frame of the machine. The flange 9 is also provided with bolt holes II' complementary to and registering with the holes 5 of th/e flange 4, and a number of tie bolts or tension bolts I2 are passed through these registering holes to prevent circumferential movement of the bowl on the main frame, and to retain the bowl in its spherical bearing seat on the frame. The upper ends of these bolts are provided with adjusting and lock nuts I3 resting on the flange 9, while the body of each bolt projects through the bolt holes and extends down alongside the exterior face of the main frame I. At the sides of each of the bolts I2 I mount two pins as I4, I4, which, as indicated in Figure 2, are secured at their upper ends in the flange 4 of the frame 3, and the bolt and its adjacent pins are each equipped with a compression spring I5. These three compression springs are coiled about the bolt and pins and the springs are interposed between the flange 4 of the main frame and a cross head I5 that has a hole to accommodate the bolt and rests upon the lower head I1 of the bolt. The lower ends of the pins project freely through holes in the cross head, and as the upper end of the bolt is firmly threaded in the flange 9 of the bowl it will be apparent that the bowl may be lifted against the tension of the springs to offer a resilient resistance to the movement of the gyratory crushing head should a large, non-breakable, stone be caught between lthe gyratory head and the concave. These resilient resistance devices, each comprising a bolt, two pins, and the three springs, are located at 4suitable intervals about the periphery -of the bowl, and the spherical bearing faces 5 and I0 insure a continuous frictional contact throughout the circular bearing of the bowl and its concave, even though a portion of the bowl is lifted, and these spherical bearing faces also guide the movement of the bowl and insure return of the bowl and concave to proper seating adjustment as the compression springs return the bowl and concave to the normal working position.

'I'he adit section of the concave is vertically ad- .instable in the bowl with relation to the exit section of the concave as well as with relation to the gyratory crushing head of the mill. For this pur.. pose the adit section comprises a cylindrical shell I9 which fits neatly within and is slidable in the bowl 1, and the shell is fashioned with an upper exterior horizontal flange I9 that projects over the ange 2I of the bowl. The flange I9 is fashioned with an outer inclined annular face 20, or tapered edge, and the flange is provided with a suitable number of lock bolts 22 that are threaded through the flange with their lower ends resting on the top of the flange 2I of the bowl. The lateral edge of the flange 2I is threaded for coaction with interior threads on the screw ring 23, which latter ring is provided with a tapered flange 24 that seats on the face 29 of the flange I9. By the joint use of the screw ring, which is provided with notches as 25 to receive a tool, and the bolts 22, the adit section of the concave may be raised or lowered for vertical adjustment within the bowl 1, and when so adjusted the section is rigidly locked within the bowl.

The shell I8 is fashioned with an integral, inner, inwardly tapering annular wall 26, above which is located the feed hopper 21 that is fashioned with an inwardly tapering annular wall and an inner ring 29 and outer annular flange 29', the latter. overhanging the upper edge of the inwardly tapering wall 25. The hopper 21 thus provides an unobstructed and free feed of material directly into the mouth of the mill from which point the material flows by gravity through the adit and exit sections of the crushing mill.

Within the inwardly tapering shell or fall 23, the outwardly flaring jaw 29 of the adit section of the concave is supported, and preferably a 1ining 30 of suitable material is interposed between the jaw and the wall, as indicated. The jaws of the concave are removable and replaceable, to compensate for wear, and the outwardly flaring jaw 29 is detachably supported in its housing or wall 25 by means of a suitable number of supporting bolts 3I, fashioned integral with, or rigid with the jaw. These' bolts project upwardly through bolt holes in the flange 28 of the hopper,

and by means of the nuts 32 the bolts are tightened to draw the jaw into rigid position against the inner face of the housing or holder 25.

The lower jaw 33, which forms the crushing face for the finer material in the exit section of the concave, is drawn and held up against the tapered wall 8 of the bowl, as best seen in Figures 5, 6, and 7, by means of pairs of spaced lugs 34 on the jaw, and bolts 35. These bolts are fashioned with wedge shaped heads 31 that flt into the tapered space 35 between the two lugs, and the bolts extend upwardly through slots 38 of the fiange 9 of the bowl. yNuts 39 that support the jaw are threaded on the projecting ends of the bolts, and these bolts, which rest on the top face of the ange 9 are employed to draw the jaw 33 into rigid contact with its housing wall 8. In this manner the jaws 33, which also are removable and replaceable to compensate for wear, are rigidly held in position, but they may readily be removed by first loosening the nuts 39 and then sliding the bolts outwardly in their slots 39 to free the wedge-heads 31 from the lugs 34.

The cone-shaped, gyratory, Crusher-head is disposed vertically within the concave, with its spindle 40 below the head, and the eccentrically operated spindle is fashioned with a taper 4I, and a lower stem 42. The crushing head 43 per se is fashioned with a central bushing 44 fitted over the upper end of the spindle, and a securing bolt 45, countersunk at 46 in the head, rigidly fastens the head on the spindle. The crushing head is fashioned with two distinct faces 41 and 48, the former being of conical shape while the latter is of frusto-conical shape, and in Figure 4 particularly, it will be noted that the face 41 has a somewhat obtuse angle compared with the lower annular face 48 whichhas a more acute angle than the upper face of the head.

The upper jaw of the gyratory head is in the form of a conical cap 49 with a skirt 50, which skirt forms the actual crushing jaw of the head in the adit concave for crushing the coarse material. The cap it will be noted forms a shield for the crown of the head and protects the crown bolt 45 and the parts joined thereby from the material, and at the same time the cap performs the functions of a distributing head to uniformly pass the material between the jaws of the gyratory head and the concave. l

At the lower edge of the skirt of this cap 49--50 I provide a flange 5l which forms an open annular grr eve in the under-cut edge of the skirt, and the 1o\ er jaw 52 of the head, which has a crushing face 53is provided with an upper flange 54 that overlaps the flange 5l, to provide a smooth, overlapping joint between the lower edge of the upper jaw and the upper edge ofthe lower jaw.

A suitable pad or filler 30 is interposed between the jaws and the cone or head, and these jaws, which rest on the faces of the head, are of substantial thickness with their crushing faces at different angles, i. e. the angle of the face 50 is more obtuse than the angle of the face 53.

These jaws are removable and replaceable, to compensate for wear, or for the purpose of making repairs, and the two jaws are joined together by their lapping flanges 5I and 54 so that they may beheld in proper position on the head, through the instrumentality of spaced lugs 55 integral with and projecting from the lower edge of the cone or head. The lower edge of the lower jaw 52 is fashioned with spaced lugs 34 (similar to the lugs 34 of the jaw 33 of the concave) and bolts 36 are mounted in the perforated lugs 55 and provided with nuts 39 that draw the wedge shaped head 31 of the bolt down into the wedge shaped space 35 between the lugs 34. A suitable number of perforated lugs 55 are fashioned integral with the lower edge of the conehead and a complementary number of bolts'and lugs 34 are provided in order that the two jaws may be secured on the top of the head.

On the lower end of the spindle is attached or mounted a hemi-spherical bearing head 56 that is seated, loosely, in a complementary bearingsocket 51, and the latter is fashioned with an integral, flat, circular plate 58. These bearing members form a pivotal support for the compound movement of the spindle, which not only revolves on its axis, but also gyrates, with the plate 58 gliding over the top surface of the bearing housing 59.

The housing 59 is provided with vertical or cylindrical walls 60, and the housing, together with the spindle and the gyratory head, are vertically adjustable with relation to the concave. To this end the housing is enclosed within a cylindrical frame-ring 6I integral with a fixed casing 62, and an adjusting, threaded bushing 63 having tool sockets 64, is mounted on exterior threads of the ring 6I. In the open bottom of the bushing an upturned annular flange 65 is provided which supports the housing of the hemi-spherical bearing of the spindle. By the use of a suitable tool or lever inserted in a socket 64 it will be apparent that the adjusting bushing 83 may be turned on the fixed ring 6l to raise, or to permit lowering of the spindle and its gyratory crushing head with relation to the concave. A suitable dust ring 66 is provided at the top of the threaded bushing 63 as a seal against the entry of dust into the threaded joint between the bushing and the ring.

As seen in Figures 1 and 3 the casing 62 is provided with an upper cylindrical bearing ring 68 and a lower cylindrical bearing ring 61, and an `eccentric bearing sleeve 69 that surrounds the spindle is journaled in these two bearing rings.

A driven gear 10, or gear ring, is fixed to the sleeve just above the lower bearing 61 and enclosed within the gear casing 52, and the upper head 1| of the latter is bolted at 12 to the casing l2. A dust plate 13 which has a central opening for the spindle, is mounted on the top of the gear casing, as a shield for the upper bearing and other parts within the casing. to prevent entry of dust-to the interior of the casing.

In Figure 1 a driving gear 14 meshes with the driven gear ring 18, and this driving gear is fixed to revolve with its horizontally disposed shaft 15 journaled in bearings 18.

One of the bearings for the drive shaft is located in a side plate 11 fitted into the gear casing 62, and the plate is fashioned with a tubular, dust-proof housing 18 that protects the enclosed shaft fromthe crushed material that falls from the crushing elements, down between the walls of the housing 3 and the casing 62. At its outer end the tubular housing is provided with a head 19 that is bolted to the horizontally disposed collar projecting outwardly from the housing 3, and an operating pulley 8| is keyed on the driving shaft exterior of the housings and driven by power from a suitable source.

A lubricating system is provided for the operating parts within the housings 60 and B2, and these parts provide dust-proof oil chambers for oil that is introduced through port 82 in the bottom of the housing 59--60. The oil passes up through a hole in the pivot plate 58 and through another hole in the spherical bearing head 56 to an alined oil duct 83 in the lower end of the spindle. At 84 the duct extends laterally through the spindle and opens into an annular oil chamber 84 formed within the eccentric sleeve and about the tapered part 4l of the spindle. The eccentric sleeve of the spindle is also provided with oil ducts 85 receiving oil from the chamber 84 and these ducts distribute oil to the bearings 61 and 680i the eccentric sleeve. An outlet port or drain 86 is provided uin the bottom of the bearing-housing 59-60 for proper disposal of the used oil.

In Figure 8 I have illustrated by the use of eight numbered circles the gradual reduction of the material as it passes between the gyratory crushing head and the concave, a choke crushing zone being indicated at the mouth of the adit zone of the mill and a free crushing zone being indicated as occupying the exit section and a portion of the adit section of the concave. A clearance space increasing in area is indicated as extending from the mouth of the adit section to the outlet of the exit section, which space is located adjacent to the concave, and a compression distance is indicated adjacent to the gyratory crushing head. The range of movement of the gyrating and revolving head is indicated by the lines denoting the open position of the jaws of the head and also the closed position of the jaws of the head.

The material flows freely, and unobstructed through the hopper 21 into the mill, and due to gravity and agitation by the gyratory head, passes down between the conical-head and the concave, forming a bed of substantial thickness on the faces `oi. the jaws of the gyratory head. The material at the mouth of the adit section of the concave substantially fills the space between the head and the concave providing a choke condition where the coarse material is crushed between the jaws of the head and concave. In the free crushing zone occupying the lower part of the adit concave and the exit section of the concave, the material is in constant contact with the head, but in contact with the faces of the section concave-jaws only during part of the closing stroke of the head. The choke crushing action of the coarse material atthe mouth of the mill thus prepares the material for free crushing in the second or exit zone where the nner material is crushed, and then falls into the receptacle 2.

By the formation of the apex Jaw "-50, or the upper jaw of the gyratory head with the lines oi' its tace on obtuse angles, the inclination o! this cone shaped Jaw provides for a downward sliding movement o1' the material on the head having a slower rate of movement than the rate of movement of the sliding material on the more inclined face 53 of the lower jaw 52 of the head. This diierence in the rate of speed oi the movement of the material on the two distinct jaws of the head, with the slower speed on the apex jaw insures suillcient time for agitation and uniform distribution oi the material, by the apex jaw, and'the movement of the material on the apex jaw of the head is retarded to prevent the crushing of more material in the adit section than can be accommodated in the exit section of the mill.

In combination with the comparatively slight inclination of the face of the conical or apex jaw of the gyratory head, the face of the iiaring jaw 29 of the adit concave-section has a more acute angle than the angle of inclination of the apex jaw, to insure the necessary nip of coarse material between the gyratory head and the concave jaw.

Thus it will be seen that the capacity of the mill depends primarily upon the diameter of the gyratory head, the angles of inclination of the two jaws of the gyratory head, the angle of inclination of the jaws of the sectional concave, and the distance or space between the gyratory head and the concave jaws.

Variations in the capacity of the mill may be accomplished by vertical adjustment of the head with relation to the concave, and vertical adjustment of the adit jaw of the concave in its relation to the exit section of the concave and the relation of the adit jaw to the gyratory head, as before described, but of course the crushing space at the lower end of the jaw 29 is never greater than the space at the intake of the exit section of the concave.

In the diagram of Figure 8 it will be apparent that the spheres or circles, representing the material, will be crushed by compression, and the size of the spheres is reduced from the diameter equal to the intake opening of the adit zone to the diameter equal to the discharge opening of the exit zone. After the crushing stroke, and as the gyrating head recedes from the concave, the bed of material rests upon the head and slides downwardly on the head, due to the fact that the rate of fall of the material under force of gravity is greater than the speed of movement of the receding head or cone face.

Thus sphere I is compressed on the closing stroke, as it is nipped between the head and the concave, to the diameter of the sphere 2 and on the opening stroke this material slides down on the face of the head to the position of 2 in which position it is seen contacting with both the head and the concave.

On the next closing stroke the sphere 2 is compressed and reduced and on the following opening stroke of the head this crushed material slides down to the position 3 substantially in contact with both the head and the concave.

Sphere 3 is `next compressed and crushed to reduced size and the material slides down the face of the apex jaw to the position of sphere 4 and not quite touching the face of the concave. Then sphere l is crushed and slides down on the i'ace of the apex jaw to position 5 where the material is shown as resting on or in contact with the head, but not contacting with the concave.

In this manner the rate of flow of the material, through the adit zone of the mill is restricted, constricted, or retarded, as before mentioned, to prevent excess feed or overleed of material from the adit zone to the exit zone.

As the material passes from the adit section and while passing through the exit section it encounters a free crushing action between the head and the concave, as is indicated by the clearance space of the exit zone and the compression distance indicated on the head, in Figure 8. Here the spheres 5, 8, 1, and 8 contact with the concave only during the closing of the jaws on the compression or crushing stroke of the head, and the clearance space indicates the freedom of ilow of the material through the exit zone. Thus the flow of material in the adit zone is restricted, constricted or retarded by the use of the small-diameter concave and the complementary, flat-faced apex-jaw of the gyrating head, so that the material rests and slides down on this flat face of the head. In the exit zone, between the larger-diameter concave and the larger-diameter, steeper-sloping, frusto-conical, lower jaw of the head, the flow of the material is less retarded, and is more free to flow by gravity than in the adit zone, and therefore the material passes more quickly through the exit zone.

As seen in Figures 4 and 8 the bell-shaped concave-section opposite the apex-jaw has a curved surface that is tangential to the face of the apex-jaw; and that the concave-section opposite the lower, steeper-sloped, jaw of the head also has an upper curved surface that merges with a plane lower surface that is tangential to the flat face of the lower jaw of the head. 'Ihese curved and tangential surfaces of the concavesections provide wider clearance spaces at the entrances of the respective zones than are present at the lower, outlet, ends of the zones. Thus the wider clearance spaces prevent over-feed to the respective zones, and the surfaces of the two concave-sections curving away from the at faces of the opposing jaws of the head provide the necessary clearance for the coarser materials to enter the respective zones. The crushed material, graded to a uniform maximum size, after passing through the exit zone, nally passes and falls by gravity, into the pit or receptacle 2 beneath the central portion of the mill.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a crushing mill the combination with a bowl, a lower frusto-conical jaw in the bowl, and means for supporting said jaw against the bowl, of an adjustable shell mounted in the howl and means for vertically adjusting the shell in the bowl, a frusto-conical upper jaw within the shell, a hopper secured to the shell, and means for securing said upper jaw to the hopper.

2. In a crushing mill the combination with a bowl and its lower, frusto-conical jaw, of a shell mounted in the bowl and adjustable means for supporting the shell on the bowl, an open, inner frusto-conicalwall within the shell. a feed hopper mounted on said wall, a frusta-conical upper jaw mounted within the Wall, and supporting bolts securing the jaw to said hopper.

3. In a crushing mill, the combination with a bowl having an upper outwardly extending threaded flange, of a shell snugly fitted within the bowl having an outwardly extending flange overhanging said bowl-flange and set bolts in the shellange engaging the bowl-flange and adapted to raise and lower the shell within thebowl, a hopper and an upper crushing jaw supported by the shell, a locking ring threaded on the threaded ilange, and said ring and shell-ange having cooperating tapered iaces to frictionally engage each other when said locking ring is in locking position.

4. The combination in a crushing mill with a concave having an upper frusto-conical Jaw and a lower frusto-conical jaw, of a gyratory head mounted within the concave and having an upper conical apex-jaw and a lower frusto-conical jaw, each of said head-jaws having a crushing face and the face of the lower jaw having a. steeper slope than the face of the apex-jaw, the face of the upper concave-jaw being curved with its lower portion substantially parallel with the lower portion of the apex-jaw, the face of the lower concave-jaw also being curved and having its lower portion substantially parallel with the face of the lower head-jaw.

5. The combination in a crushing mill with a concave having an adjustable upper frusto-conical jaw and a lower frusto-conical jaw, of a vertically adjustable gyratory head mounted within the concave and having an upper conical apexhead and a lowerfrusto-conical jaw, each of said head-jaws having a crushing face and the face of the lower jaw having a steeper slope than the face of the apex-jaw, the face of the upper concave-jaw being curved with its lower portion substantially parallel with the apex-jaw. the face of the lower concave-jaw also being curved and having its lower portion substantially parallel with the face of the lower head-jaw.

ARTHUR W. FAHRENWALD. 

